The invention relates to an improvement in a device for neutralizing military objects, the said device consisting of launching a mother rocket above the said objects and making it release an assembly of sub-munitions towards elementary targets which are mobile on the ground and are distributed in large numbers on an extended area, each of the said sub-munitions which has a military charge and is suspended from an aircraft in such a position that its firing axis forms a constant angle with the vertical comprising:
means ensuring its substantially uniform rotational movement about the vertical axis passing through its suspension point from the aircraft in such manner that, when the aircraft has a substantially uniform vertical descending movement, the firing axis effects a spiral scanning of the ground in order to search for a target; PA1 means for detecting the said target constituted by a sensor of narrow field of view comprising one or several detectors and an optical system orienting and concentrating the radiation of the detected target on the detectors; PA1 guiding means in the horizontal plane towards the detected target;
the aimed fire being started when a detection of the target is effected at an altitude which is lower than a limit imposed by the range of the military charge.
The search for important military objects situated beyond the distance of visibility (that is to say at, for example, 30 or 40 kilometers from the point of observation) is one of the missions which fall to the systems of arms with terminal guiding.
It is to be noted that said important military objects such as a group of at least a dozen tanks, an anti-aircraft base, a control station, etc . . . are characterized by elementary targets of a known nature (tank, battery, lorry etc . . . ) distributed in a large number on areas of several hectares according to well-defined deployment rules.
Devices operating according to the analysis mode described in the opening paragraph have been devised in various western countries (see French Pat. No. 2,478,297). They will hereinafter be designated by the acronym TACED (Tete Anti-Char a Effet Dirige) (anti-tank head with directed effect).
If the analysis mode by spiral scanning characterizing the TACED is sufficient to effect an aimed fire during the passage on a target, it is on the contrary poorly adaptated to the function "detection" necessary to realize the guiding. In fact at least three gaps which are inherent in said analysis mode may be mentioned:
(a) it is substantially impossible to take into account all the information available to detect the object (number of targets, deployment) since, if the detection process would be followed after the discovery of the first target, the following targets would appear one by one and the calculation of their relative positions would be inextricable;
(b) consequently, there is no criterion whatsoever to choose the target on which the guiding is to be effected. Said target will thus generally be the first target detected. In unfavourable conditions, however, it is possible that the guided sub-munition does not have the time to recapture the mobile target chosen, whereas it would have successfully tracked another target moving at the same speed.
(c) the tracking of a target necessitates an absolute reference. In the absence of an absolute reference the localization of the target is effected in a mobile reference system connected to the aircraft. Since the target can be detected only when the sub-munition is on a particular cone, the measurements of localization are not periodic and an important time may lapse between two successive localizations. During that time the mobile reference system may turn in an uncontrollable manner. The guiding movement may thus be influenced by considerable errors and, at the boundary, may be locked, bringing the sub-munition periodically at its point of departure. In these conditions the tracking is impossible. A means of escaping this defect would consist in localizing the target with respect to an absolute reference, which would no doubt introduce complex means.